Rated 8/10
I gather that this is seen as a pivotal album for the Stones.
The whole Brian Jones Question was at a critical stage -- he had founded the band, and still thought he was an important part of it, while Jagger, Richards, and their producer, Oldham, thought very differently; Jones was still contributing to songs meaningfully with his tinkering around with unusual instruments; and Jones's drug use made him unreliable and only intermittently productive.
Stylistically, this album marks a shift away from blues covers toward originals, greater variety of sound and style, and toward the prevalent tastes in the singles market of the moment.
So, the album marks a significant transitional moment.
Musically, the album is interesting in a number of ways. Lyrically, there are problems, which are not restricted to Under My Thumb.
There is also the US vs UK version of the album thing, an annoying and regular feature of the mid 1960s (Paint It Black on the US version, Mother's Little Helper on the UK).
I think I've listened to this before, and it failed to make much impact on me. They have cleaned up the sound significantly, which is a welcome feature.
Going Home is an unexpected triumph. I Am Waiting is another surprise standout. I like Lindsey Buckingham's version of that one.
Not an easy album to evaluate in some respects, but -- I think I have to respect what it has to offer, at the same time that I have long thought Under My Thumb is problematic (while its marimba sound makes it the most interesting thing on the album musically), and have long thought that Mother's Little Helper is obnoxiously judgemental about something that the speaker can not possibly know enough about to take that attitude.